Colorado State Mammal
Rocky Mountain Bighorn Sheep (common name) Ovis canadensis canadensis (scientific name) Overview The bighorn sheep is a species of sheep found only in North America. There are three distinct subspecies of the bighorn: the Rocky Mountain bighorn, the Sierra Nevada bighorn, and the desert bighorn. Bighorn sheep are named for their large, curved horns. They originally crossed over the Bering land bridge from Siberia. The population in North America peaked in the millions, and the bighorn sheep entered into the mythology of Native Americans. However, by around 1900, hunting, competition from domesticated sheep, and diseases had decreased the population to only several thousand. The Rocky Mountain bighorn has been the state animal of Colorado since 1961. Close-up STATUS Official PHYSICAL DETAILS Bighorn sheep males have large, curved horns. Females also have horns, but they are short with only a slight curvature. Bighorns range in color from light brown to grayish or dark chocolate brown, with a white rump and lining on the back of all four legs. They are relatives of goats, and have balance-aiding split hooves and rough hoof bottoms for natural grip. These attributes, along with keen vision, help them move easily about rocky, rugged mountain terrain.    Males Females Size 5–6 ft (1.5–1.8 m) 5–6 ft (1.5–1.8 m) Weight Males can occasionally exceed 500 lb (230 kg) Females can exceed 200 lb (90 kg) LIFESPAN Average lifespan in the wild is 6–15 years HABITAT Rocky Mountain bighorns are, as their name suggests, found only in the Rocky Mountains, usually above the timberline. They generally prefer extremely rugged terrain. In winter, bighorn herds move to lower-elevation mountain pastures.  Conservation efforts have restored the population. Today it is illegal to pursue, take, hunt, wound, or kill the Rocky Mountain bighorn sheep except as provided by law. BEHAVIOR Rocky Mountain bighorns are social animals, generally separated into two groups. Mature rams stay in one group, while the ewes, lambs, and young rams move about separately. The groups join during the mating season or the "rut." Prior to the rut, the rams fight to establish a dominance hierarchy that determines access to ewes for mating. It is during the pre-rut period that most of the characteristic horn clashing occurs between rams, although this behavior can occur occasionally throughout the year. When fighting for dominance, males can reach their top land speed. The animal's thick, bony skull usually prevents serious injury. The fighting continues until one ram submits and walks away. Bighorns are well adapted to climbing steep terrain, which protects them from predators such as coyotes, golden eagles, and cougars. Top land speed recorded: 20 mph (32 kph) DIET Grasses, seeds, shrubs (particularly in fall and winter), and minerals at natural salt licks. Big horns regurgitate their food to chew it as cud before swallowing it for final digestion. OFFSPRING Breeding interval: Annual Birthing period: Spring Average litter size: 1 lamb; 2 lambs are rare. TRIVIA Fights for dominance between mature male rams can last up to 24 hours. Bighorn sheep are highly susceptible to diseases carried by domestic sheep, such as scabies and pneumonia. They also often die from accidents involving rock fall or falling off cliffs. Bighorns have a complex, nine-stage digestive process that allows them to maximize removal of nutrients from food of marginal quality. A ram’s horns can weigh up to 30 pounds (14 kg), more than all the bones in his body combined.
	Click to enlarge an image Male Rocky Mountain Bighorn Sheep Female Rocky Mountain Bighorn Sheep Young Rocky Mountain Bighorn Sheep CLASSIFICATION Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Artiodactyla Family: Bovidae Subfamily: Caprinae Genus: Ovis Species: O. canadensis Subspecies: O. c. canadensis
	Data Source: U.S. Fish and Wildlife Service Author: World Trade Press